This invention generally relates to the field of woodworking and the like in which large panels or sheetgoods are cut at specific angles. Specifically, the invention relates to a sheetgood cutting table that allows such large panels, on the order of 4'.times.8', to be cut quickly and accurately at preset angles.
In home and small workshops there is often a need to make cuts in sheetgoods ranging, for example, from vertical to 45.degree.. Some sophisticated, expensive tools, such as sliding tables and laser cutters, will tend to serve the needs of large manufacturers well, but because of the size and expense of such machines, they are impractical for home use or smaller shops.
In smaller shops, the handling of the sheetgood is a prime concern. Such sheet goods are usually at least 4'.times.8' and may vary in thickness from 1/8" to 11/4". Because of their size, weight, and flexibility, these panels and sheetgoods are very difficult to handle, especially for one person. If the sheetgood is not precisely handled and guided during the cutting operation, the sheetgood will bind in the cutting tool and become damaged. Easy and precise handling is therefore critical to the accuracy of any cut.
The positioning of the sheetgood is another important concern for smaller shops. Horizontal positioning of the sheetgood may be appropriate if more than one operator is available or if time is taken to firmly secure the sheetgood with clamps, etc., before attempting a cut. Vertical and semi-vertical positioning of the sheetgood significantly eases the cutting procedure for the solo operator. Vertical and semi-vertical positioning of the sheetgood also reduce space and storage area requirements. The manner in which the sheetgood is cut, whether the sheetgood moves across the cutting tool or whether the cutting tool moves across the sheetgood, is also critical to the ease of handling and accuracy of the cut. Finally, the size and positioning of an angle measuring device, such as a protractor, are key considerations to the setup and accuracy of the angle cut.
Until now, there has been no commercially available, affordable tool for the home or small workshop that can easily handle and accurately cut angles on all types of sheetgoods, especially relatively large panels. Many panel saws that accommodate sheetgoods are commercially available, but they do not cut angles in the range of 0.degree.-45.degree.. Instead, these prior devices only cut horizontally or vertically, i.e, they only ripcut and crosscut. Many miter saws are commercially available, but these only handle relatively small workpieces, usually up to about one foot in size. Furthermore, most available tools are for saws only, and will not accommodate other cutting tools, such as routers.
One prior sheetboard cutting machine is disclosed in U.S Pat. No. 3,008,498 to Olsen. This device is said to cut sheetgoods at angles. An important drawback to this design, however, is that the cutting blade is expected to move the sheetgood on rollers while cutting the angle. Because many wood sheetgood products may weigh as much as one hundred pounds, the saw blade will flex under the force of moving the sheetgood, and the sheetgood will tend to bind during travel. These problems would only be worse on even heavier materials such as plastics. Poor movement of the sheetgood therefore makes this tool awkward and difficult to use and control, and greatly decreases the accuracy of the angle cuts.
Another saw table, disclosed in U.S Pat. No. 2,739,624 to Haddock also cuts sheetgoods at angles, but only if the sheetgood lays horizontally on the tool. This horizontal positioning decreases control and accuracy because the operator must reach across the sheetgood while operating the cutting tool. If a 4'.times.8" sheetgood is attempted to be cut, the operator's reach must be nearly six feet. This makes the operation likely to require more than one operator, reducing the useability of the tool. Furthermore, this design places a small protractor at the tool fence, at the inside edge of the sheetgood. A small error in setting is therefore magnified as the cutting tool reaches the outer edge of the sheetgood. This design feature greatly reduces the accuracy of the angle cut.
U.S. Pat. No. 2,818,892 to Price also discloses a relatively small fixture for making angled cuts but this fixture includes other design difficulties. Because of the placement of the protractor/angle measuring device, the workpiece could very well extend beyond the protractor, making it impossible to see and accurately align the cutting tool. Furthermore, this design has a double frame and has many parts that could wear quickly, increasing required maintenance and reducing useability and accuracy. Although Price shows a vertically oriented cutting frame for cutting large sheet panels, there is apparently no means for making angled cuts other than horizontal and vertical cuts with this device. The fixture which Price does disclose for making angled cuts accommodates workpieces up to about one foot in size.
The portable miter box shown in U.S. Pat. No. 2,633,162 to Neuenschwander pivots the cutting tool approximately in the center of the frame, which works adequately with relatively small workpieces, but is not a suitable design for cutting materials such as relatively large sheetgoods.